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Smoke does get in your eyes

Smokers have a twofold to threefold increased risk of developing age related macular degeneration with vision loss compared with those who have never smoked, say two studies reported in JAMA.

But doctors may find it difficult to use this latest evidence to convince smokers to give up--as the increased risk persists even after stopping smoking for more than 15 years.

In one study, researchers from the Massachusetts Eye and Ear Infirmary in Boston followed up 31 843 women from 1980 for 12 years. Results of the study showed that current and past smokers had a significantly greater risk of age related macular degeneration than women who had never smoked.

Women smoking 25 or more cigarettes a day had 2.4 times the risk of developing the condition. Women with a history of smoking had a twofold increased risk of macular degeneration, with little drop in risk even in those who had stopped smoking more than 15 years before (JAMA 1996;276:1141-6).

In a separate study more than 21 000 doctors aged between 40 and 84 who were enrolled in the physicians health study were followed up for an average of 12.2 years. Investigators found that smoking increased the risk of age related macular degeneration in a dose dependent fashion.

Current smokers of 20 or more cigarettes a day had a twofold to threefold increased risk of developing the condition with vision loss compared with those who had never smoked.

Those who smoked less than 20 a day were at no increased risk, while those with a history of smoking more than 20 cigarettes a day continued to have a 40% to 80% excess risk of age related macular degeneration for many years after stopping (JAMA 1996;276:1147-51).

Mr Michael Lavin, consultant ophthalmologist at Manchester Royal Eye Hospital, welcomed the new data. "At present anything that can reduce the frequency of age related macular degeneration is valuable because it is one of the top three causes of blindness or partial sight in the elderly. Age related macular degeneration with vision loss is a terribly difficult condition to adapt to--it cuts away at the centre vision and makes it very difficult to enjoy life as it can lead to loss of independence," he said.

Age related macular degeneration has been estimated to affect about 80% of people over 75, with the late stages of the disease affecting about 7%. The condition is also difficult to treat.

According to Mr Lavin, laser treatment and surgery to remove the fluid under the retina are current options but are not widely available. External beam irradiation, steroid treatment, and anti-androgenic treatment are currently being investigated.--ZOSIA KMIETOWICZ, medical journalist, London

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